Lawn mower cutter bar



Aug. 10, 1937. -T. B. FUNK LAWN MOWER CUTTER BAR Filed Feb. 11, 1935 Patented Aug. 10, 1931 LAWN MOWER CUTTER BAR Truman B. Funk, Jackson, Mich, assignor to "Yard-Man, Inc., Jackson, Mich, a corporation of Michigan application February 11, 1935, Serial No. 5,890

2 Claims.

This invention relates to lawn mower cutter bars and more particularly to a cutter bar including an integral cutter blade.

To my-knowledge all lawn mowers heretofore 5 manufactured having a rotating cutting reel and stationary cutter bar have been of cast iron and supported a steel cutting blade held in position by rivets or screws, or of sheet metal. The cast iron cutter bar has taken the form of a heavy,

bulky casting in order to obtain the required strength and rigidity, and the sheet metal cutter bar has lacked rigidity and permanence.

In prior practices of the above character, the weight of the cast iron cutter bar has constituted a substantial portion of the entire weight of the lawn mower. As the cutter bar is usually forward or rearward of the groundwheels the concentration of weight is not inducive' to easy handling of the lawn mower during operation. In addition, the costof machining and assembling the cutter bar and blade constitute a sizable part of the entire cost of the mower. To replace a worn cutting blade it is the usual practice to machine a new blade to enable the same to be rivited in position upon the old cutter bar.

An object of this invention is to overcome the above difliculties by providing a complete lawn mower cutter bar including the cutting blade, of a unitary strip of carbon tool steel.

Another object of this invention is to provide a lawn mower cutter bar including the cutting blade, of a unitary rolled strip of carbon tool steel having a reinforcing rib.

, A further object is to provide a unitary cutter bar including the cutting blade arranged for ready attachment to and removal from lawn mowers.

These and other objeits will be apparent from the following specification when taken with the accompanying drawing in which Fig. 1 is a plan view of my improved cutter bar,

Fig. 2 is a section on the line IIII of Fig. 1, and

Fig. 31s a partial side elevation of a lawn mower showing my improved cutter bar attached thereto,

Fig. 4 is a view similar to Fig. 2 showing a modifi'ed form of cutter bar not having a trailing edge opposite the cutting blade.

Referring particularly to Figs. 1 and 2 of the drawing the reference character I indicates the cutter bar which has a. body 2, a forwardly extending upwardly inclined cutting blade portion 3 and a rear trailing edge portion 4. The edge 5 of the, cutting blade portion 3 is ground to prothat the bar I have a carbon content of from .80

to .95 per cent. This percentage, however, is not 5 part of the invention and it is intended that any steel be used which is suitable for a shearing edge.

Disposed beneath the body portion 2. between the trailing edge 4 and the cutting blade 3 is a 10 downwardly extending rib 8, the function of which is to stiffen the bar i.

The bar I is directly supported by end plates 1 to which it is welded as shown. Bolts 8 and 9 secure the end plates 1'to the frame plates I0. 15 comprising portions of the lawn mower structure. The bolts 8 pass through-holes ii in the frame plates i0, holes l2 in the end plates 1, and are threaded into tapped holes l3 in the ribs 6. Washers l4 space the heads of the bolts 8 from the frame plates Ill. The bolts 9 pass through washers l5, adjusting eye bolts [6, adjusting slots I! in the frame plates ill and into tapped holes I8 in the end plates 1. The adjusting eye bolts pass through sleeves l9 rigidly 25 attached to the frame plates i0 and are vertically adjustable with respect thereto by the nuts 20.

It will thus be obvious that by loosening the bolts 8 and 9 and vertically adjusting the eye bolts Hi, the cutting edge 5 may be pivoted about the a bolt 8 to provide any required adjustment with respect to thecutting reel blades 2|.

According to this invention the rolled stock from which the cutter bar I is made is cut into desired lengths, drilled and tapped. Then it is 35 heat treated in the usual way to provide the cutting edge with the proper degree of hardness. The finished cutter bar is very much lighter in weight than former combined cast iron and steel types and can be produced at a much lower 40 cost due principally to reduced labor costs. Furthermore, an additional advantage of the lighter weight lies in the fact that the lawn mower on which it is used can be operated more easilyand shipping charges are reduced. While 4 it is true that according to this invention, in order to replace the cutting edge the entire cutter bar must be replaced rather than the cutting blade alone as has heretofore been done, the cost of my entire cutter bar is approximately 50 the same as the cutting blade of the prior art.

The foregoing description is illustrative only and I do not wish to be limited except by the scope of the following claims.

I claim: 68

1. An integral cutter bar and cutting blade for use in lawn mowers having a rotated cutting reel,

said..- integral structure being entirely formed from\ a section of rolled high carbon steel as dis- 5 tingulshed iroma sheet metal strip of uniiorm thickness shaped to the desired contour, in crosssection said integral structure being. of varying thickness with a well defined thickened longitudinally extending stiffening riboi substantially 10 equal width and thickness and constituting a minor portion of the width or said structure, a longitudinally extending cutting blade portion merging with said rib and being-less thanonehalf the thickness thereof, the width of said 15 blade portion being greater than said rib and terminating in a longitudinally extending upward turned cutting edge portion, excepting the thickened rib portion, said integral structure being otherwise or relatively uniform thickness in 20 cross-section.

2. In a lawn mower having a'cutting reel, an integral cutter bar and cutting blade formed from a section of rolled'high carbon steel, said section I being relatively thin and of substantially uniform cross-section throughout the major portion oi its width to define a cutting blade portion terminating in an upward turned edge and an intermediate web portion, a rib of substantially greater thickness than said blade and web portion into which said web portion merges, said rib being disposed along one side of said web and blade portions and acting to stiflen the same, plates attached at opposite ends thereof tor receiving means for adjusting said,cutter bar and cutting blade, said rib at the ends of said section being shaped to receive pivots about which the cutter'bar and cutting blade is oscillated to provide adjustment. Y

TR, B. FUNK. 

